[Speed] Mirage deprecation - update (cloudflare#25144)

Author: ToriLindsay

src/content/docs/speed/optimization/images/mirage.mdx

@@ -1,19 +1,22 @@
 ---
 pcx_content_type: reference
 source: https://support.cloudflare.com/hc/en-us/articles/219178057-Configuring-Cloudflare-Mirage
-title: Cloudflare Mirage
+title: Cloudflare Mirage (deprecated)
 learning_center:
   title: What is lazy loading?
   link: https://www.cloudflare.com/learning/performance/what-is-lazy-loading/
 sidebar:
   order: 3
+  label: Mirage
+  badge:
+    text: Deprecated
 
 ---
 
 import { FeatureTable, GlossaryTooltip, Render } from "~/components"
 
 :::caution[Deprecation notice]
-Mirage is being deprecated and will be removed on September 15, 2025.
+Mirage was deprecated on September 15, 2025.
 As an alternative, Cloudflare recommends using [lazy loading](/images/tutorials/optimize-mobile-viewing/) and [responsive images](/images/transform-images/make-responsive-images/) to optimize image performance for all devices.
 :::